HDFS DataNode无法启动，抛出java.io.EOFException

浏览HDFS网页时，404，然后去服务器看下果然发现没有datanode进程，然后去看下日志

日志部分内容：

java.io.EOFException: End of File Exception between local host is: "ubuntu/127.0.1.1"; destination host is: "localhost":9000; : java.io.EOFException; For more details see: http://wiki.apache.org/hadoop/EOFException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.apache.hadoop.net.NetUtils.wrapWithMessage(NetUtils.java:801)
at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:765)
at org.apache.hadoop.ipc.Client.getRpcResponse(Client.java:1493)
at org.apache.hadoop.ipc.Client.call(Client.java:1435)
at org.apache.hadoop.ipc.Client.call(Client.java:1345)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:227)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:116)
at com.sun.proxy.$Proxy15.sendHeartbeat(Unknown Source)
at org.apache.hadoop.hdfs.protocolPB.DatanodeProtocolClientSideTranslatorPB.sendHeartbeat(DatanodeProtocolClientSideTranslatorPB.java:154)
at org.apache.hadoop.hdfs.server.datanode.BPServiceActor.sendHeartBeat(BPServiceActor.java:459)
at org.apache.hadoop.hdfs.server.datanode.BPServiceActor.offerService(BPServiceActor.java:581)
at org.apache.hadoop.hdfs.server.datanode.BPServiceActor.run(BPServiceActor.java:775)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.io.EOFException
at java.io.DataInputStream.readInt(DataInputStream.java:392)
at org.apache.hadoop.ipc.Client$IpcStreams.readResponse(Client.java:1794)
at org.apache.hadoop.ipc.Client$Connection.receiveRpcResponse(Client.java:1163)
at org.apache.hadoop.ipc.Client$Connection.run(Client.java:1059)

 

经网上资料整合原因：

　　HDFS每次format，都会生成一个namenodeid，存在缓存目录的dfs/data下，多次format后，ID不一，导致无法启动datenode

解决：每次format后，清理缓存目录，缺点是会导致缓存数据丢失，如果有不让数据丢失的办法，欢迎告知，拜谢！